conogive {conogive}

Estimate a Congeneric Normal-Ogive Model

Description

conogive is used to estimate congeneric normal-ogive models (McDonald, R. P. (1997)).

Usage

conogive(data, use = "complete.obs", ...)

Arguments

data

A data frame of observations or a named list with elements lambda, sigma, and cuts. See the details.

use

Passed to stats::cov; defaults to "complete.obs".

...

Passed to psych::fa, where fm = "ml" by default.

Details

The data argument can be either a list containing the parameters of a normal-ogive model, or raw data. If actual data is passed to data, it is passed to psych::polychoric to estimate its polychoric correlation matrix and cutoffs. This is passed to psych::fa to do a barebones multivariate normal-ogive model. The ... arguments are passed to psych::fa, which is called with fm = "ml" by default.

Likert data should start with 1, not 0.

Value

An object of class conogive.

References

McDonald, R. P. (1997). Normal-ogive multidimensional model. In W. J. van der Linden & R. K. Hambleton (Eds.), Handbook of Modern Item Response Theory (pp. 257–269). Springer. https://doi.org/10.1007/978-1-4757-2691-6_15 Moss, J. (2020). Please avoid the standardized alpha and the ordinal alpha. https://psyarxiv.com/nvg5d

Examples

if(require("psychTools")) {
  extraversion = psychTools::bfi[c("E1", "E2", "E3", "E4", "E5")]
  extraversion[, "E1"] = 7 - extraversion[, "E1"] # Reverse-coded item.
  extraversion[, "E2"] = 7 - extraversion[, "E2"] # Reverse-coded item.
  fit = conogive(extraversion)
}